Doc addition - make-pango-font-tree

[Risto Vääräniemi]

Dear All,

In 2006 Eyolf made a extensive study about the combined effect of the
set-global-staff-size and the Pango font definitions in
make-pango-font-tree [1]. It seems that this manual section has not
been yet updated. I was struggling with the same thing yesterday and
because I've got no internet connection at home I could not get things
right: I set both make-pango-font-tree numerical parameter to the
set-global-staff-size value and got some very big note heads. :-)

Should the Section 1.8.2 Text markup - Font selection have a text
describing how the make-pango-font-tree parameters should be used.
Something like:

%%%%
If the set-global-staff-size is used for changing the global staff
size, the \myStaffSize should be set to the same value. The value 20
inside the make-pango-font-tree should be kept unchanged. In addition,
the set-global-staff-size should be defined before the font
definition.
%%%%

Probably under the "roman: foo bla bar" image.

Feel free to change the text or send you opinions.

-Risto

[1] http://lists.gnu.org/archive/html/lilypond-user/2006-08/msg00275.html